The present invention relates to the general field of designing a composite material blade for a rotor wheel of a turbine engine.
The intended field is that of moving blades of gas turbines for aeroengines or for industrial turbines.
Proposals have already been made to make turbine engine blades out of composite material, in particular out of ceramic matrix composites (CMCs). Reference may be made in particular to document FR 2 939 129 which describes fabricating a turbine engine blade out of composite material comprising fiber reinforcement densified by a matrix.
It is known that metal blades present mechanical strength characteristics that become greatly degraded at high temperatures, which makes it necessary to optimize the geometrical profile of such a blade in hot zones, specifically in its airfoil, in order to reduce the mechanical stresses to which the blade is subjected in operation.
Unlike metal blades, CMC blades present mechanical strength characteristics that are better at withstanding high temperatures, thereby shifting the critical zone of the blade to its root (which is a cold portion). High mechanical stresses appear at the root of the blade while the blade is in rotation.